# my_module.py

def greet(name):
    """This function greets the person passed in as a parameter."""
    return f"Hello, {name}!"


def add(x, y):
    """This function returns the sum of two numbers."""
    return x + y


def write_to_file(filename, content):
    """This function writes the given content to the specified file."""
    with open(filename, "w") as f:
        f.write(content)


def read_from_file(filename):
    """This function reads the content of the specified file and returns it."""
    try:
        with open(filename, "r") as f:
            return f.read()
    except FileNotFoundError:
        return "File not found."

def main():
    """Main function that runs when the script is executed directly."""
    name = "Alice"
    print(greet(name))

    num1 = 5
    num2 = 3
    print(f"The sum of {num1} and {num2} is: {add(num1, num2)}")

    file_content = "This is some content written to a file."
    write_to_file("example.txt", file_content)
    print(f"Content written to file: {file_content}")

    read_file_content = read_from_file("example.txt")
    print(f"Content read from file: {read_file_content}")

    read_file_content = read_from_file("nonexistent.txt")
    print(f"Content read from file: {read_file_content}")


if __name__ == "__main__":
    print("This script is being run directly.")
    main()
else:
    print("This script is being imported as a module.")